<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        a:link {
            /* 访问前 */
            color: red;
        }

        a:visited {
            /* 访问后 */
            color: green;
        }

        a:hover {
            /* 悬停 */
            color: blue;
        }

        a:active {
            /* 点击 */
            color: orange;
        }


        a {
            color: red;
        }

        a:hover {
            color: green;
        }
    </style>
</head>

<body>
    <a href="#">aaaaaaaaaaaaa</a>
</body>

</html>